Apparatus for applying insulating coverings on electrical conductors



May 11 1926.

B. MI A. TREBES APPARATUS FOR APPLYING INSULATING COVERINGS ON ELECTRICAL CONDUCTORS Filed Nov. 5, 1925 2 Sheets-Sheet 1 //7Ve/7f0/ Emma/M4. f/efies A If May 11 1926.

B. M. A, TREBES APPARATUS FOR APPLYING INSULATING COVERINGS ON ELECTRICAL CONDUCTORS Filed Nov. 5, 1925 2 Sheets-Sheet 2 m 0 6 iw 7 r n H I 6, I 2 m ,0 -u w 7 5 6 a 7% 2 m 5 6 km WWW A 7 m Patented May 11, 1926. 3

01 OAK PARK, ILLINOIS, ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW BRUNO MAX ALFRED TREBES,

YORK.

APPARATUS FOR APPLYING PATENT OFFICE.

YORK, N. Y., A CORPORATION OF NEW msunn'rnm covnnmes N nnncrnronr. connuc'rons.

Application filed November 5, 1925. Serial No. 67,124.

This invention relates to apparatus for applying insulating coverings on electrlcal conductors, and more particularly to apparatus for applying gutta percha to short lengths of submarine cables.

Electric signalling conductors laid beneath large bodies of water may in some instances comprise a copper conductor, a covering of gutta percha applied to the conductor, and suitable protecting materials, such as creosoted jute and heavy iron armoring wire around the gutta percha. These cables are subject to conditions which frequentl y cause injuries and even breaks therein, making it necessary to remove the mjured portion from the water onto the deck of a specially designed ship for the purpose of making the necessary repairs. The copper conductor is easil spliced by either soldering or welding ut the gutta percha covering is extremely diificult to apply. manual method of applying gutta percha over these joints has been used for a great number of years with varying degrees of success depending on the skill of the operator. Various mechanical substitutions for the manual method have been tried but they have not met with complete success.

The object of the present invention is to apply insulating materials on electrical con ductors, better, more quickly, and more economically than The invention contemplates the provision of a machine consisting of a chamber containing an extrusion mechanism and ar-' ranged with a holder to receive a split extruding die having an interior annular recess in communication with a passageway from the extrusion chamber through which a compound such as gutta percha is caused to envelop the portion of a signalling conhas been heretofore possible.

Fig. 2 is a vertical sectional view taken on the line 22 of Fig. 1, part of the figure, however, being in elevation to more clearly illustrate the features thereof;

Fig. 3 is a perspective view of a portion .of a die which is used in connection with the machine;

Fig. 4 represents a sectionof a conductor after the signalling conductor has been Referring now in detail to the drawings in which like numerals are employed to designate like members throu hout the several views, and more particular y to Figs. 1 and -2, the numeral 10. refers to the base of the A extruding portion of the machine suitably secured to a table or operators bench (not shown). The base 10 supports a chamber 1.1 integral therewith, in which is supported an extrusion screw- 12 which is adapted to be revolved by a handle 13. A hopper portion 16 integral with thechamber 11 isadapted to receive plastic material 17 for extrusion through portions of the machine now to be described.

A die holding member 19 slotted at 20, is"

secured to the chamber 11 and is provided with a longitudinal recess 21 which receives plastic material forced therethrough by the screw 12. A die generally designated by the numeral 25 is'tapered to fit into a similarly tapered opening provided therefor in the die holding member 19. is formed in two sections 26, 26, each of which is shaped in the manner indicated in Fig. 3. Each die section is provided with a longitudinal aperture, and these apertures cooperate to form a tubular recess for the reception of a conductongenerally designated by the numeral 27. An annular recess 30 extends around the central portion of the die which is cut away at 31 and 32 forming ports which communicate with the slot 21, in the die holding member, and the annular recess a plurality of dowel pins 35, 35 are provided'to insure proper assembling of the two segments of the die. An electric heating element 37 of any suitable type which is The die 25 clamps 55, for gr these clamps being prefera connected to terminals 38 leading to a source of power not shown) is provided for heating the chamber 11 to keep the materlal 17 at the required plasticity.

The conductor 27 is adapted to be inserted in the die in a manner to be described thereto by thumb nuts 54, 54. The conductor holding members 53 .are provided with 'ppingb the conductor,

ly arranged so, that the conductor can be inserted therein simultaneously with the lateral insertion thereof through the slot 20. A screw threaded inthe member 51 and rotatably journaled'in one of the conductor holding members 53 is provided with a handle 62 by means of which the screw can be turned to move the slide 50, together with the conductor 27 in relationship to the extrudmg portion of the machine.

In the use of the machine for the purpose of applying gutta percha over joined portions in submarine cables the operation is as follows: The two portions 65 and 66 of the conductor are shaped, as shown particularly in Fig. 4:, so as to present a large surface to each other and are then joined by soldering or otherwise and the joined portion covered by a spiral wrapping of fine wire 67. Theblunt endsof the gutta percha insulation 70 are then tapered down as shown in Fig. 5, and the conductor coated with Chattertons Compound, a mixture of pine tar and gutta percha, in order to make the gutta percha adhere tightly to the metal conductor. After these operations the'conductor 27 is inserted laterally through the slot 20 and engaged securely by the clamps:

55, the die ,25 having been previously removed. The two segments of the die are then assembled around the conductor, exterior of the die holder,with the small end of the tapered die in proximity to the large end v-of the tapered opening in the die holder. The die is then slid along the conductor into the tapered openinfi in the holder, the die being held frictiona y'to maintain the ports 31' and 32 in registration with the longitudinal recess 21 in the die holding memer." The'insulated vconductor is then posi tioned to bring the'beginm'ng of one of the tapered portions ofthe in'sulationin alignment with the annular recess 30 in the die,

and the gutta percha 17 having been previously brought to the desired temperature to make it sufliciently lastic and binding,

the handle 13is turn to force the gutta percha through therecess 21 into the annu- 1,5ss,s15 1 lar recess 30 in the die. This tends to force the gutta percha along the tubular recess and between the interior wall of the die and the conductor. When this takes place the handle 62 is turned to advance the uncoated portion of the conductor through the die, thereby producing an even coating of the gutta percha thereon in the manner shown in Fig. 6. The movement of the conductor, together with the surface tension between the gutta percha and the interior of the die prevents flow of the gutta percha in a direction the reverse of that in which the conductor is advanced.

.In theuse of a machine embodying the present invention for repairing of thegutta ercha insulation in submarine cables a oint free from air blisters and other undesirable features is uniformly obtainable.

The machine does in a few minutes the work which has heretofore required considerable time to accomplish, and produces a more uniform product than has heretofore been obtainable.

The gutta percha applied to they joint with the machine can be utilized for the purpose when it is at the same high temperature as that employed in the factory for originally sheathing the conductor, this temperature having been found to result in the most desirable gutta percha coating. The eifect of the use of gutta percha for repair sections, at a high temperature, is to obtain a perfect joining of the old'and repair sections without the existence of any strain be-' tween the two sections. In a hand applied joint the gutta percha must be applied at a lower temperature, and a strain is developed in the repaired section because the material is forced into union with the old section of gutta percha when in a condition. of insuflicient plasticity. This strain tends to make the repair section of gutta percha insulation pull away from the old section thereof and this tendency is increased as the temperature is lowered.

Although specific reference has been made throughout the specification to the use of a machine embodying the present invention for the pur use of repairing the gutta percha covering 0 submarine cables, it is obvious that it may have considerable utility in the repalring of any class of electrical conductors ,m'sulated with a plastic material.

short lengths of conductors with insulating material; Examples oft-his use would bein submarine cable factories where the gutta percha-insulated core is produced in a number of sections and the sections eventually joined before-the subsequent operations of armoring the completed core. The invention is to be limited therefore not by the detailed description but only as definedlin the appended claims.

What is claimed is 2' 1. A machine for applying insulating material on an electrical conductor, which comprises a die designed topermit lateral insertion of the electrical conductor, and means for forcing the material into the die.

2. A machine for applying plastic insulation on an electrical conductor, which comprises a die designed to permit lateral insertion of the electrical conductor, means for forcing the plastic insulation into the die,

and means for causing relative movement between the conductor and the die.

3. A machine for applying plastic insulation on an electrical conductor, which comprises a die designed to permit lateral insertion of the electrical conductor, means for forcing the plastic insulation'into the die, means for holding the conductor and centering it with respect to the die, andmeans for moving the conductor relative to the die.

4. A machine for repairing plastic insulation on an electrical conductor, which comprises a split die member, a holder therefor having an opening to permit lateral insertion of the conductor and the die "designed to be inserted around the conductor and secured in the holder, an extruding passageway in the holder leading to the die portion of the die member, and means in- 1 eluding an extruding worm for forcing the .die, a holder for the machine for repai'rin plastic insulation on an electrical con uctor, which comprises a. split die having an interlor annular recess and ports in the side walls thereof communicating with the recess, a holder for the die having a longitudinal recess communicating with the ports in the side wall of the die, and means forextruding the plastic insulation through the longitudinal recess and ports into the annular recess.

6. A machine for repairing plastic insulation on an comprises a split die having a tubular longitudinal passage, an annular" interior recess forming an enlarged section in the tubular passage and ports communicating with the recess being provided in the side walls of the die designed to permit lateral insertion of a conductor and provided with a longitudinal recess communicating withthe ports, an extruding ,chamber, an extruding worm forcing the plastic insulation,through the longitudinal recess and ports into the annular recess in the die, and means for advance ing the conductor. relative to thedie while the plastic insulation is being extruded.

In witness whereof, I hereunto subscribe my name this 21st day of October A. D.,

- BRUNO MAX ALFRED TREBES.

electrical conductor, which therein for continuously- 

